Fuel control for internal combustion engines



p 15, 1964 F1 BOTTORFF ETAL 3,148,671

FUEL CONTROL FOR INTERNAL COMBUSTION ENGINES File d May 14, 1963 I; I 9 8 I T0 cmauneron ,2 IL oven FUEL RETURN.

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2f 38 7 15 FUEL RETURN 1 Z ATTORNEY United States Patent 3,148,671 FUEL CONTROL FOR INTERNAL COMBUSTION ENGINES Frank Bottorfl, 7420 Briar Road, Philadelphia, Pa., and Frank Haig, 3133 Bristol Road, Cornwall Heights, Pa.

Filed May 14, 1963, Ser. No. 280,216 4 Claims. (Cl. 123-198) It is a Well known fact that internal combustion engines can be seriously damaged if their operation is continued when the oil pressure has dropped to a predetermined degree.

One object of the present invention is to devise a novel valve assembly connected in the fuel to the engine, between the fuel pump and the carburetor and controlled by the oil pressure in the oil line from the engine, to automatically shut off the fuel feed to the carburetor and bypass the fuel anterior to the carburetor, back to the tank. Thus, the only fuel available at this time for operating the engine is the amount of fuel contained in the carburetor, and therefore the engine will stop after the motor vehicle has run only a short distance and the engine will not be injured.

A further object is to devise a novel valve assembly having a diaphragm subjected to the oil pressure and actuating a valve controlling passage of fuel from the pump to the carburetor.

A further object is to devise a novel valve assembly having a diaphragm subjected to the oil pressure of the engine, actuating a valve, which when the ignition is shut off, or the oil pressure drops below a predetermined minimum, the fuel which is in the fuel line between the carburetor and the fuel pump and which is normally under pressure in a hot engine, is automatically returned to the fuel tank through a by-pass in the valve assembly.

A further object is to devise a novel arrangement and construction of the component parts of a valve assembly connectible in a fuel line and controlled by a predetermined drop in oil pressure.

With the foregoing and other objects in View, as will hereinafter clearly appear, our invention comprehends a novel fuel control for internal combustion engines and more particularly for those of the modern high speed type.

For the purpose of illustrating the invention, we have shown in the accompanying drawings preferred embodiments of which We have found in practice to give satisfactory and reliable results. It is, however, to be understood that the various instrumentalities of which our invention consist can be variously arranged and organized, and the invention is not limited, except by the scope of the appended claims, to the exact arrangment and organization of these instrumentalities as herein set forth.

FIGURE 1 is a schematic view of a valve embodying our invention as connected in an internal combustion engine.

FIGURE 2 is a longitudinal section of the valve, With the valve in open position to feed fuel to the carburetor, the section being taken on line 2-2 of FIGURE 6.

FIGURE 3 is a longitudinal section similar to FIG- URE 2, but with the valve in closed position.

FIGURE 4 is an exploded view of component parts of the valve.

FIGURE 5 is a section on the line 55 of FIGURE 2.

FIGURE 6 is an end elevation.

FIGURE 7 is a section on the line 7-7 of FIGURE 3.

Similar numerals of reference indicate corresponding parts.

Referring to the drawings:

A fuel tank 1 has a fuel line 2 leading to the engine 3, and provided with a conventional fuel pump 4 leading to the carburetor 5. The engine also has a conventional iceoil line 6. Our novel valve mechanism is subjected to and controlled by the oil pressure in the oil line 6 and is interposed between the fuel pump 4 and the carburetor 5.

The valve has a housing 7, provided at one end with an annular flange 8, having a diaphragm 9, interposed between the flange 8 and the annular flange 16, of a fitting 11 and being held in assembled condition by fasten ing means 12, the fitting 11 being provided with a tapped opening 13, to receive the oil pressure line 6 leading from the engine.

The central portion of the fitting 11, adjacent the diaphragm, is provided with a recessed portion 14 to permit movement of the diaphragm and an annular recess 15 to provide clearance. The annular flange 8 of the housing 7 is also provided at its central portion adjacent the diaphgram with a similar recess 16. An inlet port 17 is provided in the housing 7 positioned near the annular flange 8, and a discharge port 18 is positioned at the opposite end of the housing 7. The port 17 is connected with a line 19 leading from the fuel pump and the port 18 is connected to a discharge line 20 leading to the carburetor, both ports 17 and 18 communicating with the bore 21 of the housing 7. The bore 21 is provided With a fitting 22, having an annular groove 23, the fitting 22 having a press fit in the bore 21. The annular groove 23 communicates with the inlet port 17, and is provided with a number of ports 24 arranged in spaced relationship around the periphery of the annular groove and drilled at an angle to communicate with an annular recess 25 positioned at one end of the fitting 22. The recess 25, at its outer end, is provided with an, annular ridge 26, forming a valve seat. The fitting 22 is provided with a bore 27 adapted to receive a tube 28, fixed in a conventional manner to the diaphragm 9, such as by a back-up plate 29, fixed at one end of the tube 28, the tube being threaded at 30 to receive a nut 31 and washer 32. The tube 28 is provided with a bore 33 adapted to receive adjacent its closed end a helical compression spring 34 and a valve stem 35, in engagement with spring 34 at one end an at its opposite end is provided with an annular flange 36 forming a valve head. At the end nearest the valve head 36, the stem 35 is provided with an annular recess 37 adapted to receive and retain an O ring 38.

The annular flange 36 forming the valve head is adapted to seat against the annular ridge 26 which forms the valve seat, and is held in closed position against the seat when the ignition is off, or when there is no oil pressure, by a helical compression spring 39, bearing against an end closure 40, adapted to be received in a bore 41 of the housing 7, provided with a sealing ring 42 in an annular recess 43 and provided with an annular flange 44 provided with fastening means 45 to retain the end closure in assembled condition with the housing 7. The closure 40 is provided with a bore 46 of reduced diameter, communicating at its inner end with the bore 21 of the housing 7, and terminates in a flat face 47. The opposite end of the bore 46 terminates in a port 48 adapted to receive a by-pass line 49 which is connected to the fuel line 2.

The operation is as follows:

Assuming now that the valve mechanism is connected as hereinbefore explained, the valve during normal operation of the engine is in the position shown in FIGURE 2, or in its open position and remains in this position, assuming there is sufficient oil pressure.

If the oil pressure drops to a dangerous degree, or if the ignition is turned off, then the valve assumes the position shown in FIGURE 3, as the spring 39 closes the valve against its seat, thus closing the line from the fuel pump. As the valve closes against its seat the forward extension of the valve stem containing the .0 ring 3 38 is retracted from the face 47 of the end closure 40, thus permitting the fuel which was in the line from the valve to the carburetor to drain back through the bore 46, as shown by the arrows in FIGURE 3, to the line leading back to the fuel tank 1.

The helical spring 34, retained in the bore of the tube 28, acts not only to help retract the diaphragm, but takes up any slack which may exist in the valve stem and provides for a more resilient action of the valve.

In the modern high compression engine, operating under high temperature, the fuel in the line between the fuel pump and the carburetor sometimes reaches boiling temperature with a consequent great increase in pressure. When the ignition is shut off, this increase in pressure forces the float valve of the carburetor off of its seat, thus flooding the carburetor. This, of course, causes hard starting if an attempt is made to start the motor immediately after this flooding and while still hot, with a consequent waste of fuel. The valve of the present invention eliminates this condition by relieving the pressure in the line leading to the carburetor, resulting not only in a saving in fuel, but also in easier starting.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A fuel control for an internal combustion engine, having a fuel supply, having a feed line from the fuel supply to the engine and containing a fuel pump and a carburetor posterior to the fuel pump, a valve mechanism having a body portion and a chamber with an inlet communicating with said feed line between the fuel pump and the carburetor and having an outlet forming a portion of the feed line to the carburetor, a valve controlling said inlet and outlet and controlled by the engine oil pressure and a by-pass leading from said valve chamber to said feed line, whereby when the oil pressure drops to a low pressure injurious to the engine the fuel between 4 the carburetor and fuel pump is by-passed back to the fuel supply and when the fuel retained in the carburetor is exhausted the engine stops.

2. The means defined in claim 1, wherein the valve mechanism has a diaphragm subjected on one side to oil pressure and operatively connected at its other side with spring means which tension both the valve and the diaphragm.

3. The means defined in claim 1, wherein a diaphragm is mounted at one end of the body portion and has one end of a tube fixed to it, a fitting through which said tube extends having a valve seat and an annular groove and ports from said groove to said valve seat, a valve cooperating with said seat and having a stern slidable within said tube, a spring in the tube between the valve stem and the diaphragm, and a spring acting against the head of the valve and tending to move it towards its seat.

4. The means defined in claim 1, wherein a diaphragm is mounted on the body portion subjected on one side to engine oil pressure, a tube having one end fixed to the diaphragm, a flitting in which said tube is slid able and having a valve seat, a valve having its stem slidable in said tube, having a head to engage said valve seat, said body portion having an end closure with a relief port controlled by said valve stem.

References Cited in the file of this patent UNITED STATES PATENTS 1,173,415 Day et a1 Feb. 29, 1916 1,473,303 Lightford Nov. 6, 1923 2,225,175 Koerner Dec. 17, 1940 2,734,496 Hammond Feb. 14, 1956 3,107,693 Puster Oct. 22, 1963 FOREIGN PATENTS 951,216 France Apr. 11, 1949 

1. A FUEL CONTROL FOR AN INTERNAL COMBUSTION ENGINE, HAVING A FUEL SUPPLY, HAVING A FEED LINE FROM THE FUEL SUPPLY TO THE ENGINE AND CONTAINING A FUEL PUMP AND A CARBURETOR POSTERIOR TO THE FUEL PUMP, A VALVE MECHANISM HAVING A BODY PORTION AND A CHAMBER WITH AN INLET COMMUNICATING WITH SAID FEED LINE BETWEEN THE FUEL PUMP AND THE CARBURETOR AND HAVING AN OUTLET FORMING A PORTION OF THE FEED LINE TO THE CARBURETOR, A VALVE CONTROLLING SAID INLET AND OUTLET AND CONTROLLED BY THE ENGINE OIL PRESSURE AND A BY-PASS LEADING FROM SAID VALVE CHAMBER TO SAID FEED LINE, WHEREBY WHEN THE OIL PRESSURE DROPS TO A LOW PRESSURE INJURIOUS TO THE ENGINE THE FUEL BETWEEN THE CARBURETOR AND FUEL PUMP IS BY-PASSED BACK TO THE FUEL SUPPLY AND WHEN THE FUEL RETAINED IN THE CARBURETOR IS EXHAUSTED THE ENGINE STOPS. 